Limit clutch control for dozer blade cable lift

ABSTRACT

An automatic power release for the cable drum clutch of a bulldozer blade cable lift assembly consisting of a reciprocal actuator supported from the stationary block of the cable lift assembly and an abutment carried by the travelling block of the cable lift assembly. One end of a pull cable is attached to the actuator and trained to the rear of the associated bulldozer and attached to a plunger-actuating mechanism including a plunger actuated thereby and operatively associated with the cable drum clutch of the cable lift assembly. The abutment, when the travelling block approaches the upper block, is engageable with the actuator to shift the latter and movement of the actuator is transmitted through the cable attached thereto for inwardly displacing the associated plunger and releasing the cable drum clutch.

United States Patent [72] Inventor Woodrow Regenbrecht Sealy, Tex. [21] Appl. No. 887,074 [22] Filed Dec. 22, 1969 [45] Patented Dec. 14, 1971 [73] Assignee Maurice A. Lehmann Houston, Tex. a part Interest 54] [LIMIT CLUTCH CONTROL FOR DOZER BLADE CABLE LIFT 2 Claims, 6 Drawing Figs.

[52] U.S. Cl 254/173, 254/188, 254/166, 254/190 [51] Int. Cl 866d 1/48 [50] Field ofSearch 254/173, 172,187, l85,l88,189,166, 190

[56] References Cited UNITED STATES PATENTS 896,038 8/1908 Newlon 254/173 2,973,942 v 3/1961 Schaper 254/188 FOREIGN PATENTS 1,067,463 6/1954 France 254/173 604,387 10/1934 Germany.... 254/173 1,073,709 1/1960 Germany.... 254/173 1,126,101 3/1962 Germany 254/173 Primary Examiner--Harvey C. Hornsby Attorneys-Clarence A. O'Brien and Harvey 13. Jacobson ABSTRACT: An automatic power release for the cable drum clutch of a bulldozer blade cable lift assembly consisting of a reciprocal actuator supported from the stationary block of the cable lift assembly and an abutment carried by the travelling block of the cable lift assembly. One end ofa pull cable is attached to the actuator and trained to the rear of the associated bulldozer and attached to a plungerac tuating mechanism including a plunger actuated thereby and operatively associated with the cable drum clutch of the cable lift assembly. The abutment, when the travelling block approaches the upper block, is engageable with the actuator to shift the latter and movement of the actuator is transmitted through the cable attached thereto for inwardly displacing the associated plunger and releasing the cable drum clutch.

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Lllh/llllll @UU'INCH CUNTRDL FOR BlLE CUE hllll 'll The instant invention is designed to automatically disengage the cable drum clutch of cable-operated heavy equipment accessories such as the cable lift assembly of the blade on a bulldozer. When a bulldozer blade is provided with a cable lift assembly, an upper stationary block is provided in addition to a lower travelling block which is attached to the dozer blade. The lift cable is reeved through the blocks and wound on the cable drum of the bulldozer. However, should the bulldozer blade be lifted to high, the lower travelling block will engage and be prevented against further upward movement by the upper stationary bloclt. When this occurs and the cable drum clutch is not released, the clutch is overstressed and the cable is frequently broken.

The invention consists of an abutment lip welded to the inside top of the travelling block of the cable lift assembly and a reciprocal pin actuator is supported from the upper stationary block of the cable lift assembly and engageable by the abutment lip. A cable is attached to the reciprocal actuator pin and is trained over a system of sheaves to the clutch control of the cable drum at the rear of the associated bulldozer. Engagement of the abutment lip with the actuator pin before contact of the lower travelling block with the upper stationary block is operative to cause the associated cable drum clutch to be released thereby preventing upward movement of the lower travelling block the cable lift assembly sufficient to cause the lower travelling block to abut against the upper stationary block.

The main object of this invention is to provide a limit control for the cable lift assembly of a blade carried by the front end of abulldozcr.

A further object of this invention, in accordance with the immediately preceding object, is to provide a cable drum clutch release which may not only be utilized to automatically release the clutch of a cable drum provided on a bulldozer for raising and lowering the blade of a bulldozer, but which may also be utilized to limit winding of cable on other cable-winding drums.

A still further object of this invention is to provide an automatic clutch-releasing control for the cable lift assembly of a bulldozer blade which will be readily adaptable for mounting on various makes and models of bulldozers.

A final object of this invention to be specifically enumerated herein is to provide a limit clutch control for a bulldozer blade cable lift in accordance with the preceding objects which will conform to conventional forms of manufacture, be of simple construction and automatic in operation so as to provide a device that will be economically feasible, long lasting relatively trouble-free operation.

These together with other objects and advantages which will become subsequently apparent reside in the details of con- I struction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which;

FIG. 1 is a fragmentary perspective view of the front of a bulldozer equipped with a cable lift assembly on the front end thereof and with the limit clutch control of the instant invention operatively associated with the upper stationary and lower travelling blocks of the cable lift assembly;

FIG. 2 is a fragmentary side elevational view of the front end of the bulldozer illustrating the associated components of the limit clutch control operatively associated therewith and with the bulldozer blade in a position spaced below its uppermost limit position established by the control;

FIG. 3 is a fragmentary side elevational view similar to FIG. 2 but with the bulldozer blade illustrated in its upper limit position established by the clutch control;

F IG. 4 is a fragmentary vertical sectional view taken substantially upon the plane indicated by the section line El-4 of IF l0. 2 and on somewhat of an enlarged scale;

MG. 5 is a fragmentary horizontal sectional view talren substantially upon the plane indicated by section line 5-5 of H6. 4; and HG. s is a schematic view in perspective of the entire limit clutch control of the instant invention and the related I components of the associated bulldozer.

Referring now more specifically to the drawings, the numeral Ml generally designates a conventional form of bulldoaer having a cable lift assembly referred to in general by the reference numeral 12 mounted on its forward end and a powered cable drum assembly referred to in general by the reference numeral M mounted on its rear end.

The cable lift assembly includes an upper stationary mount 11h supported from the forward end of the bulldozer l0 and from which an upper stationary block 20 is mounted by means of a horizontal transverse pivot pin 22. The bulldozer w includes a blade 2% to which a lower travelling block 26 is secured and a lifting cable 28 has one end secured to the stationary block as at 30 with the adjacent end portion of the cable 28 reeved through the blocks 20 and 26 and the remote end of the cable 28 passed about a pair of pulleys 32 and 34 supported from the front of the bulldozer w and through a guide tube 36 extending longitudinally along the right-hand side of the bulldozer Ml. After passing through the guide tube 36 the rear end of the cable passes about a pair of rear pulleys 38 and 40 and is thereafter wound on the drum A2 of the cable drum assembly M.

The cable drum assembly M is conventional in design and includes a self-energizing brake and a clutch (not shown). The clutch includes a clutch release M and the operator of the bulldozer llll is provided with a control lever shiftable between a clutch-engaged position, a neutral position, brake release position and an extreme brake release position. When the control lever (not shown) is in the clutch-engaged position, the clutch is engaged whereby the drum a2 may be rotated by the engine of the bulldozer in order to wind the cable 23 on the drum 42 so as to lift the blade 24. When the control lever is in a neutral position, the clutch is released and the brake is engaged and when the control lever is in the brake release position, the cable unspools from the drum 42. Finally, when the control lever is in the extreme brake release position, the drum can be turned by hand with the engine stopped.

The foregoing is to be considered :as conventional and as representative of a caterpillar bulldozer.

The limit clutch control of the instant invention is referred to in general by the reference numeral 50 and includes a mount 52 secured to the rear face of the stationary bloclr 2t) by means of suitable fasteners 5d. The mount 54 supports a vertically disposed and reciprocal actuator pin 56 and the upper end of the pin 56 projects above the mount 52 and has a laterally projecting lug 58 secured thereto by welding and the lug 58 has a countersunk bore 60 formed therethrough. One end of a pull cable 64 extends through the bore 60 and includes a conical enlargement 66 thereon seated in the bore 60 and the mount 52 further includes a housing portion 68 in which a pulley wheel 70 is journaled. The end of the pull cable be adjacent the mount 52 is passed about the pulley 70 and the clutch control includes a further pulley 72 joumaled within a housing 71 mounted on front of the bulldozer 110 by means of fasteners 73 and about which the pull cable Ml also passes. After passing about the pulley 72, the pull cable M enters the inner end 74 of the forward transversely extending end section 76 of a guide tube referred to in general by the reference numeral 78. The outer end of the transverse end 76 opens into a housing 77 in which a pulley 79 is journaled and the main portion or section of the guide tube 71% extends longitudinally of the bulldozer Ill rearwardly from the housing 77 and tenninates at its rear end as at $2 adjacent a guide pulley supported from the bulldozer 10 about which the rear end portion of the pull cable passes.

A spring-biased actuator assembly referred to in general by the reference numeral as is supported from the cable drum assembly housing and includes a series of pivotally interconnected lever to which the rear end of the pull cable w ll is at tached. The actuating assembly includes an adjustable length 'pin or plunger 88 reciprocal through the housing of the cable drum assembly 14 and engageable with the clutch release member or control 44. The actuating assembly 86 is operative to inwardly displace the actuating pin 88 upon a pull on the pull cable 64. An abutment lip 90 is welded on the rear face of the travelling block 26 and is engageable with the lower end of the pin 56. Accordingly, it may be seen that upward movement of the lower travelling block 26 to its uppermost limit position illustrated in FIG. 3 of the drawings will cause the abutment lip 90 to engage the pin 56 and to upwardly displace the latter whereby the adjacent end of the pull cable 64 will be elevated so as to exert a pull on the actuating assembly 86 through the pull cable 64 to thereby inwardly displace the actuating pin 88 so as to shift the clutch release member 44 to the release position. Of course, the abutment lip 90 engages the pin 56 and sufficiently upwardly displaces the latter to cause the cable drum clutch to be released before the lower travelling block 26 is elevated sufficiently to abut against the upper stationary block 20. Thus, it may be seen that the control 50 is operatively to automatically release the clutch of the cable drum assembly 14 in response to upward movement of the lower travelling block 26 to a position spaced but slightly below its uppermost position defined by its abutting engagement with the upper stationary block 28.

It may therefore be seen that the control 50 is operative to prevent the clutch of the cable drum assembly 14 from being overstressed and the lifting cable 28 from being broken due to the powerful cable drum assembly 14 attempting to further elevate the blade 24 after the lower travelling block 26 has been displaced upwardly sufficiently to contact the upper stationary block 20.

The inner end of the section 76 is threaded into the housing 71 and the outer end of the section 76 is telescoped into the housing 77. Further, the forward end of the main portion or section of the guide tube is telescoped into the rear of the housing 71 and the housing 77 is secured to the bulldozer by means of a fastener 81. a

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In combination with a tractor of the type including an upper front stationary pulley block and a lower movable lifting pulley block, an elongated cable having one end portion reeved about said blocks and the terminal end thereof anchored relative to one of said blocks, a cable drum carried by said tractor including a clutch provided with a mechanically operableclutch release mechanism, the other end portion of said cable beingguidingly supported from and extending rearwardly along said tractor to and being wound on said drum for raising said movable block in response to winding said cable on said drum, said clutch release mechanism including a movable actuator portion, an actuator movably supported from said stationary block, an abutment supported from said movable block and engageable with said actuator to shift the latter from an inactive position to an active position in response to movement of said movable block into closely spaced relation with said stationary block, said actuator por-' tion being shiftable between release and applied positions, and elongated flexible cable means operatively connected between said actuator and said actuator portion for shifting the former to its release position in responsive to movement of the actuator portion to its active position, said motion-transmitting means comprising an elongated pull member, said pull member comprising a flexible pull cable, said tractor including a plurality of cable guide means spaced longitudinally therealong, said pull cable being reeved relative to said cable guide means between saidactuator and said actuator portion or guided longitudinal shifting of said pull cable relative to said cable guide means, said clutch including a housing, said actuator portion comprising a reciprocal rod shiftable inward relative to said housing when shifted to its release position, an actuator assembly supported from said housing and operative ly connecting said motion-transmitting means to said actuator portion for inward displacement of said rod in response to upward displacement of said actuator relative to said stationary block, said guide means including rigid cable-guiding and protecting tube sections stationarily supported from said tractor and through which a major portion of said pull cable extends.

2. The combination of claim 1 wherein said guide means includes at least two of said tube sections including interconnected relatively angulated adjacent ends, a pulley journaled from said adjacent ends of said tube sections and about which said cable is reeved, and a pair of pulleys supported adjacent the remote ends of said tube sections and about which said cable is reeved. v 

1. In combination with a tractor of the type including an upper front stationary pulley block and a lower movable lifting pulley block, an elongated cable having one end portion reeved about said blocks and the terminal end thereof anchored relative to one of said blocks, a cable drum carried by said tractor including a clutch provided with a mechanically operable clutch release mechanism, the other end portion of said cable being guidingly supported from and extending rearwardly along said tractor to and being wound on said drum for raising said movable block in response to winding said cable on said drum, said clutch release mechanism including a movable actuator portion, an actuator movably supported from said stationary block, an abutment supported from said movable block and engageable with said actuator to shift the latter from an inactive position to an active position in response to movement of said movable block into closely spaced relation with said stationary block, said actuator portion being shiftable between release and applied positions, and elongated flexible cable means operatively connected between said actuator and said actuator portion for shifting the former to its release position in responsive to movement of the actuator portion to its active position, said motion-transmitting means comprising an elongated pull member, said pull member comprising a flexible pull cable, said tractor including a plurality of cable guide means spaced longitudinally therealong, said pull cable being reeved relative to said cable guide means between said actuator and said actuator portion for guided longitudinal shifting of said pull cable relative to said cable guide means, said clutch including a housing, said actuator portion comprising a reciprocal rod shiftable inward relative to said housing when shifted to its release position, an actuator assembly supported from said housing and operatively connecting said motion-transmitting means to said actuator portion for inward displacement of said rod in response to upward displacement of said actuator relative to said stationary block, said guide means including rigid cable-guiding and protecting tube sections stationarily supported from said tractor and through which a major portion of said pull cable extends.
 2. The combination of claim 1 wherein said guide means includes at least two of said tube sections including interconnected relatively angulated adjacent ends, a pulley journaled from said adjacent ends of said tube sections and about which said cable is reeved, and a pair of pulleys supported adjacent the remote ends of said tube sections and about which said cable is reeved. 